Clinical assessment after total hip arthroplasty using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire.

Aims: The aim of this study was to evaluate clinical outcomes using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ).

Methods: 100 consecutive patients at 6 months after total hip arthroplasty (THA) were evaluated.

Results: The improvement rate for the pain subscale was significantly higher than that for the movement and mental subscales.

Rotational Acetabular Osteotomy for Osteoarthritis with Acetabular Dysplasia: Conversion Rate to Total Hip Arthroplasty within Twenty Years and Osteoarthritis Progression After a Minimum of Twenty Years.

Background: We investigated the rate of conversion to total hip arthroplasty by twenty years and radiographic findings at a minimum of twenty years after rotational acetabular osteotomy.

Methods: Between June 1986 and August 1991, we performed 172 rotational acetabular osteotomies in 168 patients with acetabular dysplasia. Of those, ninety-three hips (ninety-one patients), including twenty-three hips with pre-osteoarthritis, twenty-nine with initial osteoarthritis, and forty-one with advanced osteoarthritis, had clinical and radiographic findings available.

Does rotational acetabular osteotomy affect subsequent total hip arthroplasty?

Introduction: Rotational acetabular osteotomy (RAO) has been used successfully in patients with developmental dysplasia of the hip (DDH). However, some patients are forced to undergo total hip arthroplasty (THA) because of the progression of osteoarthritis. We evaluated the effect of previous RAO on the outcome of THA performed for degenerative arthritis secondary to DDH, comparing outcomes for patients with THA and prior RAO versus outcomes for patients with THA and no prior RAO.

Bone remodeling after a mean of 10 years in diaphyseal cortical defects repaired with femoral revision using bypass fixation of extensively porous-coated stems with high stiffness.

Introduction: Femoral component revisions with extensively porous-coated stems have shown promising clinical results, although there are still concerns over stress-shielding.

Materials And Methods: We retrospectively reviewed data for 18 patients undergoing femoral component revisions with extensively porous-coated stems with high stiffness. The average length of follow-up was 10 years (range 6-13.

Retrieval analysis of new-generation yttria-stabilized zirconia femoral heads after total hip arthroplasty.

Zirconia femoral heads were introduced for total hip arthroplasty (THA) with the expectation of lower polyethylene (PE) wear and better clinical results. Because several studies reported poor survivorship of yttria-stabilized zirconia-PE THA, we investigated a new-generation yttria-stabilized zirconia head (diameter, 26 mm) manufactured by NGK Spark Plug. We retrieved six zirconia heads at revision THA after they had been in place for a mean of 8.

Cementless anatomic total hip femoral component with circumferential porous coating for hips with developmental dysplasia: a minimum ten-year follow-up period.

Anatomic femoral components are optimized for primary osteoarthritis, and few long-term results for their use are available for developmental dysplasia of the hip (DDH). We reviewed 135 uncemented total hip arthroplasties in which an anatomic femoral component was used in 106 patients with DDH, excluding femurs with neck-shaft angles of >160° and femurs with anteversion of >50°. The mean age of patients at surgery was 49.

How far above the true anatomic position can the acetabular cup be placed in total hip arthroplasty?

Introduction: There is controversy about which is more suitable for determining correct socket position in patients with severe bone deficiency of the acetabular roof because of developmental dysplasia of the hip (DDH): the anatomic centre of hip rotation or a high centre. 


Method: We evaluated the relationship, in 200 hips, between the centre of rotation and presence of the Trendelenburg sign to determine the upper limit of cup position from the standpoint of hip-abductor strength. 


Results: Of the 200 hips, 20 (10%) showed a positive Trendelenburg sign.

Wear comparison between conventional and highly cross-linked polyethylene against a zirconia head: a concise follow-up, at an average 10 years, of a previous report.

We previously reported the results of wear comparison at a minimum of 5 years between highly cross-linked polyethylene (HXLPE) and conventional polyethylene (PE) against a zirconia femoral head. We now report the mean wear at 10 years for 52 patients (56 hips) of the original cohort of 61 patients (65 hips) who had undergone primary total hip arthroplasty at our hospital between November 1999 and August 2000. The mean steady-state linear wear rate of HXLPE was 0.

A radiological study of the true anatomical position of the acetabulum in Japanese women.

There is sometimes uncertainty concerning the correct socket position prior to total hip arthroplasty (THA). We conducted a study to determine the hip centre in Japanese women in order to define the true anatomical position of the acetabulum. The study involved 200 consecutive female patients in whom the contralateral hip joint was normal or was prearthritic and who underwent unilateral THA.

Osteoarthritis hip joints in Japan: involvement of acetabular dysplasia.

Background: We conducted a nationwide epidemiologic study regarding hip osteoarthritis (OA) in Japan, and a previous report found these patients to be unique in comparison to Caucasians. This report focused on the data regarding each hip joint, and the involvement of acetabular dysplasia with hip OA was analyzed.

Methods: Seven hundred twenty OA hips were examined.

Prevention of steroid-induced osteonecrosis by intravenous administration of vitamin E in a rabbit model.

Background: We focused on vitamins with marked antioxidant potency to see whether their use might prevent the development of steroid-induced osteonecrosis.

Methods: Fifteen Japanese white rabbits weighing about 3.5 kg were injected once into the right gluteal muscle with methylpred-nisolone (MPSL) 40 mg/kg (S group).

Should the well-fixed, uncemented femoral components be revised during isolated acetabular revision?

Introduction: The results of isolated acetabular revision performed in 35 patients (36 hips) were monitored from 3 to 10 years. All femoral components were well fixed and not removed or revised during index surgery.

Method: All revision acetabular implants were cementless, using a porous-coated hemispheric cup with or without bone graft.

Analysis of interobserver reliability for radiographic staging of coxarthrosis and indexes of acetabular dysplasia: a preliminary study.

Background: We are planning a multicenter survey on coxarthrosis and acetabular dysplasia in Japan. To collect reliable data, we performed a preliminary study to elucidate the observer agreement on assessment items.

Methods: We collected radiographs of hip joints in eight patients with various findings of coxarthrosis.

Wear comparison between a highly cross-linked polyethylene and conventional polyethylene against a zirconia femoral head: minimum 5-year follow-up.

Highly cross-linked polyethylene (HXLPE) was developed to reduce wear of articular bearing surface in total hip arthroplasty patients. Several studies have shown reduced wear of HXLPE compared with conventional polyethylene; however, these studies had used HXLPE in combination with a Co-Cr metal head. The purpose of this study was to compare the 5-year in vivo wear of HXLPE with that of conventional PE using a zirconia femoral head.

A new cementless total hip arthroplasty with bioactive titanium porous-coating by alkaline and heat treatment: average 4.8-year results.

A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years.

Revision total hip arthroplasty by nonmodular short and long cementless stems.

Background: The choice of appropriate implant for reconstruction during revision total hip arthroplasty (THA) is controversial. We use proximally porous-coated cementless short stems and fully porous-coated cementless long stems depending on the state of bone loss during revision surgery.

Methods: Between January 2000 and December 2003, a total of 21 cementless femoral revision arthroplasties using cementless stems were performed, and 20 of the cases were followed up for 2-6 years (mean 4.

Minimum ten-year results of a porous acetabular component for Crowe I to III hip dysplasia using an elevated hip center.

We conducted a retrospective study of the placement of porous-coated acetabular components using screws at more than 20 mm above the teardrop without structural bone graft for dysplastic hips to determine long-term outcome. Thirty hips (29 patients) were monitored for a mean of 15.2 years (range, 10.

Component alignment in revision total knee arthroplasty using diaphyseal engaging modular offset press-fit stems.

We performed a retrospective study of the radiographic position of femoral and tibial components in a series of revision total knee arthroplasties using diaphyseal-engaging, press fit, modular stems. Fifty-two consecutive revision cases were performed. Femoral and tibial component alignment was measured preoperatively and postoperatively.

[Oxidative stress on idiopathic osteonecrosis].

The increasing incidence of steroid-induced osteonecrosis of the femoral head is a recent and emerging problem. In-depth pathogenesis, however, has not been well understood. We focused on oxidative stress, which was reported to be involved in many diseases, and conducted animal studies to investigate it.

The unstable total knee arthroplasty: causes and cures.

Surgery for the unstable total knee arthroplasty requires a deep understanding of the causes and a plan that specifically addresses them. Isolated ligament reconstructions and polyethylene insert exchanges generally do not work. Patients may experience "buckling" from pain, flexion contracture, recurvatum, or patellar problems.

The relationship between stem subsidence and improvement in the radiolucency in polished tapered stems.

We studied the relationship between stem subsidence and improvement in the initial radiolucency at the bone-cement interface in polished- and rough-surface stems. Stem subsidence was seen in 34 of 42 hips (81.0%), and improvement in the initial radiolucency was seen in 15 hips (35.